[PATCH 4/4] drm/scheduler: do not keep a copy of sched list

[Christian König]

Am 06.12.19 um 18:33 schrieb Nirmoy Das:
> entity should not keep copy and maintain sched list for
> itself.

That is a good step, but we need to take this further.

The sched_list is static for the whole device and we shouldn't allocate 
it inside the context at all.

Christian.

>
> Signed-off-by: Nirmoy Das <nirmoy.das at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c  | 11 ++++++++---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h  |  1 +
>   drivers/gpu/drm/scheduler/sched_entity.c | 12 +-----------
>   3 files changed, 10 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> index c7643af8827f..1939b414d23b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> @@ -71,7 +71,6 @@ static int amdgpu_ctx_priority_permit(struct drm_file *filp,
>   static int amdgpu_ctx_init_entity(struct amdgpu_ctx *ctx, u32 hw_ip)
>   {
>   	struct amdgpu_ring *rings[AMDGPU_MAX_RINGS];
> -	struct drm_gpu_scheduler *sched_list[AMDGPU_MAX_RINGS];
>   	struct amdgpu_device *adev = ctx->adev;
>   	unsigned num_rings = 0;
>   	unsigned num_scheds = 0;
> @@ -129,16 +128,21 @@ static int amdgpu_ctx_init_entity(struct amdgpu_ctx *ctx, u32 hw_ip)
>   			break;
>   	}
>   
> +	ctx->sched_list = kcalloc(num_rings,
> +				  sizeof(struct drm_gpu_scheduler *), GFP_KERNEL);
> +	if (ctx->sched_list == NULL )
> +		return -ENOMEM;
> +
>   	for (i = 0; i < num_rings; ++i) {
>   		if (!rings[i]->adev)
>   			continue;
>   
> -		sched_list[num_scheds++] = &rings[i]->sched;
> +		ctx->sched_list[num_scheds++] = &rings[i]->sched;
>   	}
>   
>   	for (i = 0; i < amdgpu_ctx_num_entities[hw_ip]; ++i)
>   		r = drm_sched_entity_init(&ctx->entities[hw_ip][i].entity,
> -				ctx->init_priority, sched_list, num_scheds, &ctx->guilty);
> +				ctx->init_priority, ctx->sched_list, num_scheds, &ctx->guilty);
>   	if (r)
>   		goto error_cleanup_entities;
>   
> @@ -228,6 +232,7 @@ static void amdgpu_ctx_fini(struct kref *ref)
>   		for (j = 0; j < amdgpu_sched_jobs; ++j)
>   			dma_fence_put(ctx->entities[0][i].fences[j]);
>   	kfree(ctx->fences);
> +	kfree(ctx->sched_list);
>   	kfree(ctx->entities[0]);
>   
>   	mutex_destroy(&ctx->lock);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
> index da808633732b..9fd02cc47352 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
> @@ -44,6 +44,7 @@ struct amdgpu_ctx {
>   	spinlock_t			ring_lock;
>   	struct dma_fence		**fences;
>   	struct amdgpu_ctx_entity	*entities[AMDGPU_HW_IP_NUM];
> +	struct drm_gpu_scheduler	**sched_list;
>   	bool				preamble_presented;
>   	enum drm_sched_priority		init_priority;
>   	enum drm_sched_priority		override_priority;
> diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
> index f9b6ce29c58f..c84a9a66f7f0 100644
> --- a/drivers/gpu/drm/scheduler/sched_entity.c
> +++ b/drivers/gpu/drm/scheduler/sched_entity.c
> @@ -56,8 +56,6 @@ int drm_sched_entity_init(struct drm_sched_entity *entity,
>   			  unsigned int num_sched_list,
>   			  atomic_t *guilty)
>   {
> -	int i;
> -
>   	if (!(entity && sched_list && (num_sched_list == 0 || sched_list[0])))
>   		return -EINVAL;
>   
> @@ -67,17 +65,10 @@ int drm_sched_entity_init(struct drm_sched_entity *entity,
>   	entity->guilty = guilty;
>   	entity->num_sched_list = num_sched_list;
>   	entity->priority = priority;
> -	entity->sched_list =  kcalloc(num_sched_list,
> -				      sizeof(struct drm_gpu_scheduler *), GFP_KERNEL);
> -
> -	if(!entity->sched_list)
> -		return -ENOMEM;
> +	entity->sched_list =  sched_list;
>   
>   	init_completion(&entity->entity_idle);
>   
> -	for (i = 0; i < num_sched_list; i++)
> -		entity->sched_list[i] = sched_list[i];
> -
>   	if (num_sched_list)
>   		entity->rq = &entity->sched_list[0]->sched_rq[entity->priority];
>   
> @@ -312,7 +303,6 @@ void drm_sched_entity_fini(struct drm_sched_entity *entity)
>   
>   	dma_fence_put(entity->last_scheduled);
>   	entity->last_scheduled = NULL;
> -	kfree(entity->sched_list);
>   }
>   EXPORT_SYMBOL(drm_sched_entity_fini);
>